diff --git a/__performance_tests__/large-obj.js b/__performance_tests__/large-obj.js
new file mode 100644
index 000000000..df2475b91
--- /dev/null
+++ b/__performance_tests__/large-obj.js
@@ -0,0 +1,62 @@
+import {measure} from "./measure"
+import produce, {
+	setUseProxies,
+	setUseStrictShallowCopy,
+	enableAllPlugins
+} from "../dist/immer.cjs.production.min.js"
+
+enableAllPlugins()
+
+console.log("\n# large-obj - mutate large object\n")
+
+const MAX = 50
+
+const baseState = Object.fromEntries(
+	Array(10000)
+		.fill(0)
+		.map((_, i) => [i, i])
+)
+
+measure("immer (proxy) - with setUseStrictShallowCopy", () => {
+	setUseStrictShallowCopy(true)
+	setUseProxies(true)
+
+	for (let i = 0; i < MAX; i++) {
+		produce(baseState, draft => {
+			draft[5000]++
+		})
+	}
+})
+
+measure("immer (proxy) - without setUseStrictShallowCopy", () => {
+	setUseStrictShallowCopy(false)
+	setUseProxies(true)
+
+	for (let i = 0; i < MAX; i++) {
+		produce(baseState, draft => {
+			draft[5000]++
+		})
+	}
+})
+
+measure("immer (es5) - with setUseStrictShallowCopy", () => {
+	setUseStrictShallowCopy(true)
+	setUseProxies(false)
+
+	for (let i = 0; i < MAX; i++) {
+		produce(baseState, draft => {
+			draft[5000]++
+		})
+	}
+})
+
+measure("immer (es5) - without setUseStrictShallowCopy", () => {
+	setUseStrictShallowCopy(false)
+	setUseProxies(false)
+
+	for (let i = 0; i < MAX; i++) {
+		produce(baseState, draft => {
+			draft[5000]++
+		})
+	}
+})
diff --git a/package.json b/package.json
index dda45b834..57bb7bbeb 100644
--- a/package.json
+++ b/package.json
@@ -33,7 +33,7 @@
   "sideEffects": false,
   "scripts": {
     "test": "jest && yarn test:build && yarn test:flow",
-    "test:perf": "cd __performance_tests__ && babel-node add-data.js && babel-node todo.js && babel-node incremental.js",
+    "test:perf": "cd __performance_tests__ && babel-node add-data.js && babel-node todo.js && babel-node incremental.js && babel-node large-obj.js",
     "test:flow": "yarn flow check __tests__/flow",
     "test:build": "yarn build && NODE_ENV='production' yarn jest --config jest.config.build.js",
     "watch": "jest --watch",